Technical Field
Embodiments of the present disclosure generally relate to an image forming apparatus for forming an image on a recording medium.
Related Art
Various types of electrophotographic image forming apparatuses are known, including copiers, printers, facsimile machines, and multifunction machines having two or more of copying, printing, scanning, facsimile, plotter, and other capabilities. Such image forming apparatuses usually form an image on a recording medium according to image data. Specifically, in such image forming apparatuses, for example, a charger uniformly charges a surface of a photoconductor as an image bearer. An optical scanner irradiates the surface of the photoconductor thus charged with a light beam to form an electrostatic latent image on the surface of the photoconductor according to the image data. A developing device supplies toner to the electrostatic latent image thus formed to render the electrostatic latent image visible as a toner image. The toner image is then transferred onto a recording medium either directly, or indirectly via an intermediate transfer belt. Finally, a fixing device applies heat and pressure to the recording medium bearing the toner image to fix the toner image onto the recording medium. Thus, the image is formed on the recording medium.
For example, such image forming apparatuses may primarily transfer the toner image from the photoconductor onto the intermediate transfer belt, and secondarily transfer the toner image from the intermediate transfer bell onto the recording medium at an area of contact between the intermediate transfer belt and a transfer roller through an electrostatic transfer process. In the electrostatic transfer process, a secondary transfer bias is applied to an opposed roller that contacts an inner circumferential surface of the intermediate transfer belt to sandwich the intermediate transfer belt with the transfer roller, thereby forming the area of contact between the intermediate transfer belt and the transfer roller. In order to enhance transferability of the toner image onto the recording medium P, for example, a superimposed bias may be used as the secondary transfer bias, in which an alternating current voltage is superimposed on a direct current voltage. The intermediate transfer belt may be constructed of a plurality of layers which includes, e.g., a base layer and a top layer resting on the base layer. The base layer may be an endless belt formed into a loop. The top layer has a greater elasticity than the elasticity of the base layer, and rests on an outer circumferential surface of the base layer.
Such an intermediate transfer belt may maintain a relatively high durability with the durability of the base layer while reliably transferring the toner image onto the recording medium, particularly onto a recording medium having a rough surface, with the elasticity of the top layer. The top layer of the intermediate transfer belt has an elasticity to adhere to recesses on the rough surface of the recording medium, helping reliable transfer of toner to the recesses.